• 제목/요약/키워드: Discrete-time systems

검색결과 960건 처리시간 0.028초

시변 시간 지연을 갖는 불확실한 이산 시간 선형 시스템의 견실 안정성 (Robust Stability of Uncertain Discrete-Time Linear Systems with Time-Varying Delays)

  • 송성호;박섭형;이봉영
    • 제어로봇시스템학회논문지
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    • 제5권6호
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    • pp.641-646
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    • 1999
  • This paper deals with the robust stability of discrete-time linear systems with time- varying delays and norm-bounded uncertainties. In this paper, the magnitude of time-varying delays is assumed to be upper-bounded. The sufficient condition is presented in terms of linear matrix inequality. It is also shown that the robust stability of uncertain discrete-time linear systems with time-varying delays is related with the quadratic stability of uncertain discrete-time linear systems with constant time delay.

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MULTIPLE VALUED ITERATIVE DYNAMICS MODELS OF NONLINEAR DISCRETE-TIME CONTROL DYNAMICAL SYSTEMS WITH DISTURBANCE

  • Kahng, Byungik
    • 대한수학회지
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    • 제50권1호
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    • pp.17-39
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    • 2013
  • The study of nonlinear discrete-time control dynamical systems with disturbance is an important topic in control theory. In this paper, we concentrate our efforts to multiple valued iterative dynamical systems, which model the nonlinear discrete-time control dynamical systems with disturbance. After establishing the validity of such modeling, we study the invariant set theory of the multiple valued iterative dynamical systems, including the controllability/reachablity problems of the maximal invariant sets.

2차 시스템에 대한 이산시간 외란 관측기의 분석 (Analysis of Discrete-Time Disturbance Observer for Second-Order Systems)

  • 양광진;최영진;정완균
    • 제어로봇시스템학회논문지
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    • 제9권6호
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    • pp.425-434
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    • 2003
  • The disturbance observer(DOB) has been widely used in high speed and high precision motion control applications and the characteristics of DOB have been investigated in depth. Though most of DOB's have been implemented as the discrete-time form in digital devices, we are still short of the researches on discrete-time DOB (DDOB) in spite of rich references on continuous-time DOB. In this paper, we discuss about the disturbance rejection property and measurement noise effect of discrete-time DOB. Especially, we will focus on revealing the role of sampling time in designing the discrete-time DOB and show the validity of analysis through simulations and experiments for optical disk drive systems.

Dynamic Feedback Linearization of Nonlinear Discrete - Time Systems with 2 Inputs

  • Cho, Hyung-Joon;Ryu, Dong-Young;Park, Se-Yeon;Lee, Hong-Gi;Kim, Yong-Min
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.172.3-172
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    • 2001
  • In this paper, we find the necessary and sufficient conditions of linearization of nonlinear discrete-time systems with 2 inputs using the restricted class of dynamic feedback. That is, this paper is the discrete version of [2]. The results we obtain for discrete-time nonlinear systems are, however, quite different from that of continuous-time case.

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A design of discrete time nonlinear control system with disturbances using model following method

  • Zhang, Yuan-Sheng;Okubo, Shigenori
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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    • pp.239-242
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    • 1996
  • A model following control system(MFCS) can give general output signals following desired ones. In previous studies, a method of nonlinear MFCS was proposed by S.Okubo[1]. In this paper, the method of nonlinear MFCS will be extended to discrete time nonlinear systems. It is easy to extend the method to discrete time systems. But in the case .gamma.=1 discrete time systems, the proof becomes difficult, because the transfer function from f(v(k)) to v(k) can't be a positive real function. In this case, to ensure that internal states are stable, a new criterion is proposed.

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시변시간지연을 갖는 이산시간 선형시스템의 점근안정도 (Asymptotic Stability of Discrete Time Linear Systems with Time Varying Delays)

  • 송성호;김점근;강창익
    • 대한전기학회논문지:전력기술부문A
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    • 제48권5호
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    • pp.580-585
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    • 1999
  • This paper deals with the stability of discrete time linear systems with time varying delays in state. In this paper, the magnitude of time-varying delays is assumed to be upper-bouded. The stability of discrete time linear systems with time-varying delays in state is related with the stability of discrete time linear systems with constant time delay in state. To show this, a new Lyapunov function is proposed. Using this Lyapunov function, a sufficient condition for the asymptotic stability is derived.

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Discrete-Time Sliding Mode Control for Robot Manipulators

  • 박재삼
    • 한국산업정보학회논문지
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    • 제16권4호
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    • pp.45-52
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    • 2011
  • In the real-field of control cases for robot manipulators, there always exists a modeling error, which results the model has the uncertainties in its parameters and/or structure. In many modem applications, digital computers are extensively used to implement control algorithms to control such systems. The discretization of the nonlinear dynamic equations of such systems results in a complicated discrete dynamic equations. Therefore, it will be difficult to design a discrete-time controller to give good tracking performances in the presence of certain uncertainties. In this paper, a discrete-time sliding mode control algorithm for nonlinear and time varying robot manipulators with uncertainties is presented. Sufficient conditions for guaranteeing the convergence of the discrete-time SMC system are derived. As example simulations, the proposed SMC algorithm is applied to a two-link robotic manipulator with unknown dynamics. The results of the simulation indicate that the developed control scheme is effective in manipulators and electro-mechanical system control.

Identification and Control for Nonlinear Discrete Time Systems Using an Interconnected Neural Network

  • Yamamoto, Yoshihiro
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.994-998
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    • 2005
  • A new control method, called a simple model matching, has been recently developed by the author. This is very simple and be applied for linear and nonlinear discrete time systems with/without time lag. Based on this formulation, identification is examined in this paper using an interconnected neural network with the EBP-EWLS learning algorithm. With this result, a control method is also presented for a nonlinear discrete time system.

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The identification of continuous-time systems within a closed-loop

  • Bae, Chul-Min;Wada, Kiyoshi;Imai, Jun
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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    • pp.157-160
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    • 1996
  • Physical systems axe generally continuous-time in nature. However as the data measured from these systems is generally in the form of discrete samples, and most modern signal processing is performed in the discrete-time domain, discrete-time models are employed. This paper describes methods for estimating the coefficients of continuous-time system within a closed loop control system. The method employs a recursive estimation algorithm to identify the coefficients of a discrete-time bilinear-operator model. The coefficients of the discrete-time bilinear-operator model closely approximate those of the corresponding continuous-time Laplace transform transfer function.

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Discrete-Time Sliding Mode Controller for Linear Time-Varying Systems with Disturbances

  • Park, Kang-Bak
    • Transactions on Control, Automation and Systems Engineering
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    • 제2권4호
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    • pp.244-247
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    • 2000
  • In this paper, a discrete-time sliding mode controller for linear time-varying systems with disturbances is proposed. The proposed method guarantees the systems state is globally uniformly ultimately bounded(G.U.U.B) under the existence of time-varying disturbances.

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